New method for culture of zona-included or zona-free embryos: the Well of the Well (WOW) system.

摘要

Culture of mammalian zygotes individually and in small groups results in lower developmental rates than culture of large groups. Zona-free zygotes also have impaired developmental potential in current culture systems. This paper describes a new approach to resolve the problems, the Well of the Well (WOW) system. Small wells (WOWs) were formed in 4-well dishes by melting the bottom with heated steel rods. The WOWs were then rinsed, the wells were filled with medium, and the embryos were placed intothe WOWs. To test the value of the WOW system a 3X3 factorial experiment was performed. Presumptive cattle zygotes were cultured from day 1 to day 7 (day 0 = day of insemination) using 3 modules (single embryos, embryo groups of 5, or single zona-digested embryos) and 3 different culture systems (400μl medium, 200μl drops, or WOWs). An additional control group consisted of 40-50 embryos cultured in 400μl medium. The WOW system resulted in higher blastocyst/oocyte rates for all 3 modules (single = 59%; group of 5 = 61%; single zona-digested = 53%) than culture in drops or in wells (P<0.05 for all). The developmental rate was independent of the number of WOWs per well. The cell number of blastocysts cultured in the WOW system did not differ from thatof the controls.